Gem tester

ABSTRACT

A gem tester for testing a gem under test and a kit including a horizontal recharging stand are disclosed. In one embodiment of the gem tester, an elongated body has a line-of-sight contour tapering from a bulbous end to a radially deviating frontal nose having a probe extending therefrom. Internal circuitry measures electrical and thermal conductivity of the gem under test in order to identify the type of gem under test and drive a color control signal in response thereto. A luminescent mounting extends about the contact to provide, in response to the control signal, a color indication of the identified gem type.

PRIORITY STATEMENT & CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Patent Application No.61/356,943, entitled “Gem Tester” and filed on Jun. 21, 2010, in thenames of Kessler et al.; which is hereby incorporated by reference forall purposes.

TECHNICAL FIELD OF THE INVENTION

This invention relates, in general, to the identification of preciousdiamonds and, in particular, to gem testers for distinguishing gems suchas diamond, moissanite, and metals based upon physical conductivityproperties.

BACKGROUND OF THE INVENTION

Gemstones such as cubic zirconium and silicon carbide, commonly known asmoissanite, have become more readily available and moreindistinguishable from real diamonds. As a result, the market is floodedwith moissanite which is passed off as diamond. Advances in instrumentsand techniques are required to authenticate diamonds and preventfraudulent and mistaken sales.

SUMMARY OF THE INVENTION

It would be advantageous to achieve advances in instruments toauthenticate diamonds in order to prevent fraudulent and mistaken sales.It would also be desirable to enable an electro-mechanical solution thatwould improve operator technique when authenticating diamonds. To betteraddress one or more of these concerns, a gem tester for testing a gemunder test and a horizontal recharging stand are disclosed. In oneembodiment of the gem tester, an elongated body has a line-of-sightcontour tapering from a bulbous end to a radially deviating frontal nosehaving a probe extending therefrom. Internal circuits measure electricaland thermal conductivity of the gem under test in order to verify or,more generally, identify the type of gem under test and drive a colorcontrol signal in response thereto. A luminescent mounting extends aboutthe probe to provide, in response to the control signal, a colorindication of the verified or, more generally, identified gem type.

In one embodiment of a gem testing kit, a horizontal recharging standincludes a base having a substantially horizontal support surface and acavity defining a cradle within the base. The cradle is configured tosecurely accept the gem tester by way of an inclined support plane,opposing sidewalls, and a backstop. Electrical prongs are exposed at thebackstop in order to mate with the recharging contacts when the gemtester is cradled in the horizontal recharging stand. Upon cradling, thegem tester may be recharged. These and other aspects of the inventionwill be apparent from and elucidated with reference to the embodiment(s)described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures in which correspondingnumerals in the different figures refer to corresponding parts and inwhich:

FIG. 1 is a front perspective view of one embodiment of the gem testingkit, which includes a gem tester cradled in a horizontal testing stand;

FIG. 2A is a front perspective view of the gem tester of FIG. 1 removedfrom the horizontal testing stand of FIG. 1;

FIG. 2B is a rear perspective view of the gem tester of FIG. 1 removedfrom the horizontal testing stand of FIG. 1;

FIG. 2C is a top plan view of the horizontal testing stand of FIG. 1;

FIG. 3A is side elevation view of the gem tester of FIG. 1 in anoperational embodiment testing a gem under test;

FIG. 3B is a rear elevation view of the gem tester of FIG. 3A in theoperational embodiment testing the gem under test; and

FIG. 4 is a schematic block diagram of one embodiment of the gem tester.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts whichcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention, and do not delimit the scope of the presentinvention.

Referring initially to FIGS. 1 through 2C, therein is depicted a gemtesting kit that is schematically illustrated and generally designated10. The gem testing kit 10 includes a gem tester 12 shown cradled withina horizontal recharging stand 14, which is depicted resting on surface16, and removed therefrom. With respect to the gem tester 12, anelongated body 18 includes ends 20, 22 as well as an upper surface 24and a lower surface 26. As the illustrated embodiment shows, end 20includes a radially deviating frontal nose 28 and the end 22 includes abulbous form 30. The elongated body 18 has a tapered contour 32 from theend 22 to the end 24. A tripod contoured surface 34 is proximate to theend 20 and configured to accept a tripod hand grip. More particularly,the tripod contoured surface 34 furnishes a V-shape arcuate portion 36intersecting respective lateral grip areas 38, 40.

A probe 42 for contacting a gem under test extends from the end 20. Inone embodiment, the probe 42 includes a deflectable probe configured tobe displaced in response to contact pressure with a gem under test. Aluminescent mounting 44 is mounted proximate to the end 20 and, in theillustrated embodiment, extends from the end 20 about the probe 42 tofurnish white illuminating light to increase visibility of the probe 42and gem under test. Additionally, the luminescent mounting 44 providesan indicator light indicative of the test results and gem type (ornon-gem type) by way of color.

Display 46, which may be an LED display, is located on the upper surface24. A speaker 48 is positioned at the end 22 and a battery compartmentcover 50 is positioned on the opposite side thereto. The battery cover50 is slidably releasable to expose a battery compartment for acceptingbatteries. At end 22, a switch 52 for controlling ON/OFF, rechargingcontacts 54, and a wall adapter interface 56 are located. With respectto the weight of the weight of the gem tester 12 in one embodiment, acenter of mass 58 is proximate the end 22 when the gem tester 12 isbatteried. A cone-shaped removable protective cap 60 is releasablysecured with a snap-fit engagement to the end 20 to provide protectionthereto over the probe 42 and luminescent mounting 44.

The horizontal recharging stand 14 includes a base having a front 72 anda rear 74. A substantially horizontal support surface 76 contacts thesurface 16. A cavity 78 defines a cradle 80 within the base 70. Asillustrated, in one embodiment, the cradle 80 is configured to acceptthe gem tester 12. An inclined support plane 82 inclines from the rear74 toward the front 72 of the horizontal recharging stand 14. Opposingsidewalls 84, 86 run the length of the inclined support plane 82adjacent to and vertically from the inclined support plane 82. Abackstop 88 located near the rear 74 of the inclined support plane 82intersects the inclined support plane 82 and the opposing sidewalls 84,86. Further, the inclined support plane 82 includes a tripod supportcrest 90 which conforms to the V-shape arcuate portion 36 of the tripodcontoured surface 34 of the gem tester 12. The side walls 84, 86 includerespective indentations 92, 94 conformed to accommodate the shape of thebulbous form 30 of the end 22.

Recharging prongs 96 extend or are exposed at the backstop 88 and arepositioned to mate with the recharging contacts 54 of the gem tester 12when the gem tester 12 is cradled within the horizontal recharging stand14. A wall adapter interface 98 is located at the rear 74 of thehorizontal recharging stand 14. Although not shown in the drawings, therecharging prongs 96 and wall adapter interface 98 are electricallycoupled. Additionally, a charging light 99, which displays the status ofthe recharging proximate the front 72 of the horizontal recharging stand14 is electrically coupled to the recharging prongs 96 and wall adapterinterface 98.

In operation, in a cradled configuration, the recharging stand 14 islocated substantially horizontal to the surface 16. The lower surface 26and bulbous form 30 of the end 22 of the gem tester 12 rest in contactwith the sidewalls 84, 86 and the backstop 88. The slope of the inclinedsupport plane 82 causes the end 20 to rest at a higher elevation thanthe end 22. The tripod support crest 90 supports the V-shape arcuateportion 36 of the tripod contoured surface 34 of the gem tester 12. Inthe cradled configuration, the recharging contacts 54 touch therecharging prongs 96.

When needed, the gem tester 12 may be easily drawn from the rechargingstand 16 between the thumb and index finger. Then, the gem tester 12 maybe presented for use by way of a one-hand tripod hand grip whereby themiddle finger is placed under the V-shaped arcuate portion 36 and thethumb and forefinger are used to laterally grasp the lateral grip areas38,40 of the gem tester 12.

When use is complete, the gem tester 12 may be returned to therecharging stand 14 to the cradled position previously discussed. Asmentioned, the center of mass 58 is proximate the end 22 when the gemtester 12 is batteried. Therefore, gravity induces the bulbous form 30of the end 22 to fall into the cradle 80 at the backstop 88. This actionresults in a circuit being formed between the recharging contacts 54 ofthe gem tester 12 and the recharging prongs 96 of the recharging stand14. Once cradled, the gem tester 12 has a low profile wherein theradially deviating frontal nose 28 is at the highest point.

Referring to FIGS. 3A and 3B, and describing the testing operation ofthe gem tester 12, the battery compartment cover 50 may be temporarilyremoved and replaced to install batteries, such as three AAA 1.5 Valkaline batteries. The switch 52 may be toggled to ON to initialize thegem tester. Following a warm-up time, which may be approximately 30seconds, the gem tester 12 is ready to be used once the cone-shapedprotective cap 60 is removed. Using a comfortable grip, the hand of theuser holds the gem tester 12. As illustrated, the gem tester 12 may beheld with a one-hand tripod hand grip whereby the middle finger is placeunder the V-shape arcuate portion 36 and the thumb and forefinger areused to laterally grasp the sides of the gem tester 12 at lateral gripareas 38, 40 for handling purposes to maintain control.

Using the one-hand tripod hand grip to comfortably handle the gem tester12, a gem under test 110 may be tested. The LED display 46, which maydepict a bar graph 112, stops blinking and the ready light remains onwhen the gem tester 12 is ready for use. The user then quickly yetfirmly makes contact between the probe 42 and the table of the gem undertest 110. If a mounted gem is being tested, care is taken to not touchthe setting. Additionally, to ensure test accuracy, the gem under test110 and the setting should be at room temperature. A gem under test thatis overheated due to prolonged exposure to the probe 42 will not testaccurately. Contact is maintained for long enough to establish areading, which in one implementation is one to two seconds.

The reading process makes two measurements: thermal conductivity andelectrical conductivity. The thermal conductivity test separates diamondfrom all known diamond simulants, except moissanite, since diamondsconduct heat significantly greater than all other gemstones, exceptmoissanite. White sapphire is thermally conductive, yet not asconductive as diamond and moissanite and can be therefore easily beseparated. Since moissanite conducts electricity in varying degrees anddiamonds generally do not conduct electricity, the electricalconductivity test separates the vast majority of moissanite from diamondis the electrical conductivity test. Therefore, based upon readings fromthe conductivity and electrical tests, the type of gem or metal may bedetermined.

A line-of-sight contour 32 extends from the end 22 to the end 20 toprovide a line-of-sight (LOS). This line-of-sight contour 32 allows theprobe 42 and the luminescent mounting 44 to both be visible within thesame field of view (F) by an operator. The operator does not have tomove his or her eyes between the probe 42 and the luminescent mounting44 during operation and determination of gem type. The operator does notwant to shift his eyes away from the probe 42 to view any indicator.Often, the probe 42 is contacting a very small area and a slightmovement of the probe 42 in any direction place the probe 42 intocontact with a different surface resulting in a misleading reading.

Initially, in one implementation, the luminescent mounting may provide awhite working light (I) in the field of view (F) that is visible to theoperator along the line-of-sight (LOS) along the line-of-sight contour32. The working light illuminates the gem under test 110 to give theoperator extra visibility to ensure a proper probe contact. Based uponreadings from the conductivity and electrical tests, the type of gem ormetal may be determined by the gem tester 12. Following thedetermination, the luminescent mounting 44 provides a color indication(I) which is in the field of view (F) and visible along theline-of-sight (LOS) along the line-of-sight contour 32. For example,with respect to the indication (I), a green light (G) may indicatediamond, a blue light (B) may indicate moissanite, and a yellow light(Y) may indicate metal.

FIG. 4 depicts one embodiment of the gem tester 12 in further detail. Acircuit portion 120, including the micocontroller, which may be amicroprocessor 122, is located communicatively with circuit portions124, 126 and configured to determine or more generally identifyverified—or, more generally, identified—type and drive a color controlsignal in response thereto. The identified type being selected from aplurality of gem types including at least three materials. Additionally,the identified type may be a non-gem type, such as metal. Moreparticularly, at the center of the circuit portion 120, themicroprocessor 122, operating under the frequency source of a clock 128,processes a number of analog voltages at inputs 130, 132, 134, 136, 138to produce a number of outputs (discussed below) indicative of whether ameasurement for the gem under test is within a specific range indicatingthat the gem under test is diamond, moissanite, or other metal.

The switch 52, which may be a single pole single throw mechanicalswitch, controls the ON/OFF state of gem tester 12 and the applicationof voltage to DC-DC converter 142. A voltage source may be a batterysource 144, regular or rechargeable, or wall power provided by a walladapter converter 145 and wall adapter interface 56. The low voltageDC-DC converter 142 converts the battery source 144 or voltage suppliedby the wall adapter converter 145 to an acceptable voltage for poweringanalog and digital circuitry. A battery voltage monitor 146 is providedto detect a low voltage condition in the battery source and communicatethis information to the microprocessor 122 via the input 132. A DC-DCconverter 147 and a monitor circuit 148 are designed to condition thesignal for processing within the microprocessor 122. If low voltagecondition is detected, the audio speaker 48 or the visual display 46,both of which are connected to the microprocessor 122, may provide anindication of faulty voltage while testing is temporarily suspended bythe gem tester 12. In particular, the microprocessor 122 discontinuesgem testing when the voltage source input is below a certainpre-determined threshold.

The circuit portion 124 is electrically coupled to the probe 42, whichis shown as a deflectable probe having a spring 140 thereat, to measureelectrical conductivity of the gem under test 110. More particularly,the circuit portion 124 includes electrical components 150, includingthe DC-DC converter 147, the voltage monitor 148, and an impedancedetector 152, for applying and sampling a voltage across the gem undertest 110. The electrical components 150 successively sample the voltageacross the gem under test 110 to provide data for determining a gem typebased upon a predetermined number of samples exceeding a thresholdvoltage. As shown, the voltage monitor is coupled to the microprocessor122 by the input 132 and the impedance detector 152 is coupled to themicroprocessor by the input 134.

The circuit portion 126 is thermally coupled to the probe 42 to measurethermal conductivity of the gem under test 110. Heating components 154,including a heating resistor 156, reference thermistor 158, and ameasuring thermistor 160, heat the probe 42 and monitor the temperatureof the heated probe 42. The heater deliver circuit 162 is locatedbetween the microprocessor 122 and the heating resistor 156, thereference thermistor 158, and the measuring thermistor 160. As depicted,the heating resistor 156 is connected to the microprocessor 122 by theinput 136 and an amplifier. Similarly, the measuring thermistor 160 isconnected to the microprocessor 122 by the input 138 and an amplifier.

An LED driver 170 controls LEDs 172 in response to receiving signalsfrom the microprocessor 172. In one implementation, one LED provides awhite working light (W) and the other LEDs provide indication lightsthat indicate the composition of the gem under test. For example, agreen light (G) may indicate diamond, a blue light (B) may indicatemoissanite, and a yellow light (Y) may indicate metal. That is, in theillustrated embodiment, the LED driver 170 and LEDs 172 provide a whiteworking light as well as at least three colors of light, which areindicators of three separate types of gem or non-gem materials.

It should be appreciated that the circuit design and architecturedepicted in FIG. 4 is only exemplary and illustrative. Other designs andarchitectures are within the teachings presented herein. By way ofexample, the circuit portion 124 configured to measure electricalconductivity and the circuit portion 126 configured to measure thermalconductivity may be combined. By way of further example, illumination orindicators other than LEDs may be utilized to provide working light andcolor indicators.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is, therefore, intended that the appended claimsencompass any such modifications or embodiments.

What is claimed is:
 1. A gem tester for testing a gem under test, thegem tester comprising: an elongated body having a first end and a secondend; a probe extending from the first end of the elongated body; a firstcircuit portion located within the elongated body, the first circuitportion being electrically coupled to the probe to measure electricalconductivity of the gem under test; a second circuit portion locatedwithin the elongated body, the second circuit portion being thermallycoupled to the probe to measure thermal conductivity of the gem undertest; a third circuit portion located within the elongated bodycommunicatively with the first and second circuit portions, the thirdcircuit portion configured to determine identified type and drive acolor control signal in response thereto, the identified type beingselected from a plurality of gem types including at least threematerials; a luminescent mounting extending from the first endcommunicatively with the third circuit portion, the luminescent mountingproviding a plurality of colors corresponding to the plurality of gemtypes, the luminescent mounting lighting one of the plurality of colorsin response to receiving the color control signal; and a line-of-sightcontour extending from the second end of the elongated body to the firstend of the body, including the luminescent mounting to the probe.
 2. Thegem tester as recited in claim 1, wherein the elongated body furthercomprises: the first end having a radially deviating frontal nose; thesecond end having a bulbous form; the elongated body being tapered fromthe first end to the second end; and a center of mass being proximatethe second end when the gem tester is batteried.
 3. The gem tester asrecited in claim 1, wherein the elongated body further comprises atripod contoured surface proximate to the first end, the tripodcontoured surface configured to accept a tripod hand grip.
 4. The gemtester as recited in claim 1, wherein the probe further comprises adeflectable probe configured to be displaced in response to contactpressure.
 5. The gem tester as recited in claim 1, wherein the firstcircuit portion further comprises electrical components for applying avoltage across the gem under test, the electrical componentssuccessively sampling the voltage across the gem under test to providedata for determining a gem type based upon a predetermined number ofsamples exceeding a threshold voltage.
 6. The gem tester as recited inclaim 1, wherein the second circuit portion further comprises heatingcomponents for heating the probe and monitoring the temperature of theheated probe.
 7. The gem tester as recited in claim 1, wherein the thirdcircuit portion further comprises a microprocessor.
 8. The gem tester asrecited in claim 1, wherein the first, second, and third circuitportions are at least partially integrated.
 9. The gem tester as recitedin claim 1, wherein the luminescent mounting further comprises whitelight source for illuminating the gem under test.
 10. The gem tester asrecited in claim 1, wherein the luminescent mounting further comprisesgreen, red, and blue colors.
 11. The gem tester as recited in claim 1,wherein the gem tester identifies diamond, metal, and moissanite. 12.The gem tester as recited in claim 1, further comprising a releasablecap having a snap-fit engagement about the probe.
 13. A gem tester fortesting a gem under test, the gem tester comprising: an elongated bodyhaving a first end and a second end; a probe extending from the firstend of the elongated body; means for measuring electrical conductivityof the gem under test communicatively disposed with the probe; means formeasuring thermal conductivity of the gem under test communicativelydisposed with the probe; a circuit portion located within the elongatedbody communicatively with the means for measuring electricalconductivity and means for measuring thermal conductivity, the circuitportion configured to determine identified type and drive a colorcontrol signal in response thereto, the identified type being selectedfrom a plurality of gem types including at least three materials; meansfor providing, in response to receiving the color control signal, aplurality of colors corresponding to the plurality of gem types; and aline-of-sight contour extending from the second end of the elongatedbody to the first end of the body to the luminescent mounting to theprobe.
 14. The gem tester as recited in claim 13, wherein the means formeasuring electrical conductivity and the means for measuring thermalconductivity are at least partially integrated.
 15. The gem tester asrecited in claim 13, wherein the means for providing a plurality ofcolors further comprises means for providing green, red, and bluecolors.
 16. The gem tester as recited in claim 13, wherein the gemtester identifies diamond, metal, and moissanite.
 17. A gem testing kit,comprising, in combination: a gem tester comprising: an elongated bodyhaving a line-of-sight contour tapering from a bulbous end to a radiallydeviating frontal nose having a probe extending therefrom, a center ofmass proximate the bulbous end when the gem tester is batteried,recharging contacts are exposed at the bulbous end, an internal circuitcoupled to the contact and the recharging contacts, the internal circuitconfigured to measure electrical and thermal conductivity of the gemunder test in order to identify the type of gem under test and drive acolor control signal in response thereto, and a luminescent mountingextending from the elongated body, the luminescent mounting configuredto provide, in response to the control signal, a color indication of theidentified gem type; and a horizontal recharging stand comprising: abase having a substantially horizontal support surface, a cavitydefining a cradle within the base, the cradle configured to accept thegem tester, the cradle including an inclined support plane, opposingsidewalls and a backstop, and recharging prongs are exposed at thebackstop, the electrical prongs being positioned to mate with therecharging contacts when the gem tester is cradled within the horizontalrecharging stand.
 18. The gem testing kit as recited in claim 17,wherein the elongated body further comprises a tripod contoured surfaceproximate to the a radially deviating frontal nose, the tripod contouredsurface configured to accept a tripod hand grip.
 19. The gem testing kitas recited in claim 17, wherein the inclined support plane intersects atripod support crest, the tripod support crest conforming to the shapeof a lower portion of the tripod contoured surface.
 20. The gem testingkit as recited in claim 17, wherein the side walls further compriserespective indentations conformed to accommodate the shape of thebulbous end.
 21. A gem tester for testing a gem under test, the gemtester comprising: an elongated body having a first end and a secondend; a probe extending from the first end of the elongated body; a firstcircuit portion located within the elongated body, the first circuitportion being electrically coupled to the probe to measure electricalconductivity of the gem under test; a second circuit portion locatedwithin the elongated body, the second circuit portion being thermallycoupled to the probe to measure thermal conductivity of the gem undertest; a third circuit portion located within the elongated bodycommunicatively with the first and second circuit portions, the thirdcircuit portion configured to determine identified type and drive acolor control signal in response thereto, the identified type beingselected from a plurality of gem types including at least threematerials; a luminescent mounting mounted proximate to the first end andcommunicatively with the third circuit portion, the luminescent mountingproviding a plurality of colors corresponding to the plurality of gemtypes, the luminescent mounting lighting one of the plurality of colorsin response to receiving the color control signal; and a line-of-sightcontour extending from the second end of the elongated body to the firstend of the body, including the luminescent mounting to the probe. 22.The gem tester as recited in claim 21, wherein the elongated bodyfurther comprises: the first end having a radially deviating frontalnose; the second end having a bulbous form; the elongated body beingtapered from the first end to the second end; and a center of mass beingproximate the second end when the gem tester is batteried.
 23. A gemtester for testing a gem under test, the gem tester comprising: a bodyhaving a line-of-sight contour tapering from a bulbous end to a radiallydeviating frontal nose having a probe extending therefrom; a center ofmass proximate the bulbous end when the gem tester is batteried;recharging contacts exposed at the bulbous end; and an internal circuitcoupled to the contact and the recharging contacts, the internal circuitconfigured to measure at least one of electrical and thermalconductivity of the gem under test in order to identify the type of gemunder test and drive a color control signal in response thereto; and aluminescent mounting extending from the body, the luminescent mountingconfigured to provide, in response to the control signal, a colorindication of the identified gem type.
 24. A gem tester for testing agem under test, the gem tester comprising: a body having an end; a probeextending from the end of the body; a first circuit portion locatedwithin the body, the first circuit portion being electrically coupled tothe probe to measure electrical conductivity of the gem under test; asecond circuit portion located within the body, the second circuitportion being thermally coupled to the probe to measure thermalconductivity of the gem under test; a third circuit portion locatedwithin the elongated body communicatively with the first and secondcircuit portions, the third circuit portion configured to determineidentified type and drive a color control signal in response thereto,the identified type being selected from a plurality of gem typesincluding at least three materials; and a luminescent mounting extendingfrom the end communicatively with the third circuit portion, theluminescent mounting providing a plurality of colors corresponding tothe plurality of gem types, the luminescent mounting lighting one of theplurality of colors in response to receiving the color control signal.